In recent years, e-mail for transmitting and receiving character information via a network is in widespread use along with diffusion of computers and networking of information. The e-mail is capable of attaching various types of files in addition to a message body which is the character information. For instance, there is diffusion of an Internet FAX (abbreviated as “IFAX” hereafter) for transmitting and receiving an image by attaching a TIFF (Tag Image File Format) file as an attachment file.
The IFAX is a technology for communicating between apparatuses capable of converting the image read by a scanner to a TIFF format and transmitting it from a transmitter, reproducing the image in the TIFF format from data received by a receiver and printing it.
Here, in the case of transmitting the e-mail with a file of a large data size attached thereto, there is a possibility that delivery of the e-mail may delay due to a load applied to processing in a mail server, and if further deteriorated, the entire e-mail delivery service may stop. For that reason, in many cases, the mail server is generally set up not to receive the e-mail over a certain data size. There are the cases where, when the e-mail with an image of a large data size attached thereto is transmitted to the mail server thus set up from the IFAX, it is determined as a delivery error by the mail server.
For instance, in the case of transmitting the e-mail with an image attached thereto by using a PC, it is relatively easy to check the data size of the attached image. In the case of the IFAX, however, it is difficult to predict what the data size will be when scanning and transmitting the image, and so there is a high possibility that the above-mentioned delivery error may occur frequently. Thus, there is a proposal made as to a technology of an Internet facsimile apparatus for dividing image information of multiple pages by page and transmitting it (Japanese Patent Laid-Open No. 2000-32202).
There is also a proposal made as to a technology for, in the case of receiving e-mail data having the image information of multiple pages divided by page and transmitted, performing print and transfer processing in order of pages of original image information (Japanese Patent Laid-Open No. 2004-236005). Furthermore, there is a decided method of transmitting a piece of e-mail data by dividing it into multiple pieces of e-mail so as to synthesize received multiple pieces of e-mail data as one. In this case, message/partial as an identifier is used for MIME Content-Type (RFC 2045, RFC 2046).
RFC 2298 stipulates a specification wherein, in the case of receiving the e-mail, transmittal confirmation mail of a communication apparatus (IFAX) on a receiving side of the e-mail is sent back to the communication apparatus (IFAX) of a source of the e-mail. This specification is called MDN (Message Disposition Notification).
Here, in the case of performing transmittal confirmation of split e-mails divided into multiple pieces, the communication apparatus (IFAX for instance) on the transmitting side does not need to perform transmittal confirmation as to each piece of the split e-mails. To be more specific, the communication apparatus on the transmitting side has only to check whether or not one piece of the e-mail before being divided has been transmitted to the communication apparatus on the receiving side.
In the case where each piece of the split e-mails includes an MDN format for requesting the transmittal confirmation, however, the transmittal confirmation is requested of the communication apparatus on the receiving side according to the MDN format of each of the multiple pieces of the split e-mails.
In such a case, each time the split e-mails are received, the communication apparatus on the receiving side transmits the transmittal confirmation mail for the received split e-mails to the communication apparatus on the transmitting side accordingly. In such a configuration, the communication apparatus on the transmitting side receives multiple pieces of transmittal confirmation mail although just one request to send (RTS) consisting of the multiple pieces of the split e-mails was made. Thus, receiving processing and the like become complicated.
Even in the case where a part of the split e-mails is not transmitted from the communication apparatus on the transmitting side to the communication apparatus on the receiving side, the communication apparatus on the transmitting side receives some piece of transmittal confirmation mail. For that reason, there may be a disruption since it is not clear whether or not all the pieces of the split e-mails have been transmitted.